Woodside Optometry
(contact info removed by request)
They asked for this note above to be deleted, but you should know
that the Crizal coating from Woodside failed in a few years,
they were reluctant to replace under warranty, and the replacement
also failed in the same time frame. Coated lenses from SpecTek
have lasted far longer with no "crazing" or deterioration.

Ask for Thin&Dark lenses, or just tell them Steve Eckert referred you,
and that you want the same kind of glacier glasses for climbing.
Most photochromatic lenses don't get dark enough... or light enough.
You need something that goes from over 90% to under 10% as a
minimum range at sea level. They will get MUCH darker at elevation
because the sunlight is stronger. I greatly prefer glass to plastic
because it's more durable and won't scratch when you wipe it with
tissue paper. The plastic lenses also warped enough to produce
visible distortion when wedged into glacier glasses frames.

I don't get any money for referrals, but maybe I can get some
brownie points and they'll know what you want if you mention my name.
I spent a couple of years finding the right materials and being told that
there is only one kind of glass called 'photo brown extra' - it ain't so.

I wear mine day and night when climbing. They lighten well except
they are slow to lighten when it's very cold. I use them as my
only sunglasses to about 15k on snow. For really high elevations,
I carefully trimmed a pair of polaroid clip-ons to fit INSIDE the
photosensitive lenses. (The glass lenses darken from UV, so clipping
a pair of extra sunglasses on the outside is self-defeating.)

For frames, I used to buy the $16 nylon ones at REI - ask the guy
at the counter for the ones WITHOUT lenses. I think they may have stopped
selling the old aviator style nylon unbreakable ones. If you just have
to have expensive ones you can buy any style and knock out the
standard lenses. The places above will put lenses into whatever frames
you bring or mail in. I also have some wrap-arounds from SpecTek with
smaller clip-in lenses, but they don't have as large a viewing area.

Oakley's website
gives some description of their Plutonite proprietary curved lens and coatings.
(Click on the Frogskins Rx frame and then Frogskins on the next screen
to see a display of the lens colors that are available.)

Oakley developed a process to grind a single prescription (no bifocals) into
their radically curved lens. Their Gold Iridium Plutonite lens treatment
provided about 95% filtering of all damaging wavelengths. (We ran a test in
Europtics' lab to verify their claims on filtering.) Europtics here in
Denver took my prescription and had Oakley fit lens into their Frogskins
frame, which fit my face the best. It was about $200 total cost. It took a
little getting used to the wide curved, wraparound style Oakley lens, but
the peripheral vision difference compared to normal "flat" lens glasses is
amazing.

The frame fits my face well enough that I have nearly no light
leakage around the temples, so they actually provide more coverage and eye
protection than my old glacier glasses with the leather side shields. The
big surprise was something about their Gold Iridium coating (I think it's
maybe the texture of the coating?) is highly resistant to fogging. When the
lens do fog up, just pulling them slightly away from your face lets enough
air circulate that the fog almost always dissipates quickly. Another benefit
is under cloudy conditions, the lens coating seems to brighten the view and
you don't get the usual dark tunnel vision effect that's common with regular
really dark sunglasses.

Oakley also provided a bomber hard shell carrying case. I haven't tested
their warranty, but apparently they will repair or replace almost anything
that goes wrong with their products.
Just another option to consider. Glacier glasses that perform well are not
only a necessity but a welcome luxury!